Didn't you miss z?

:thumbsup:

I would guess the problem is the battery use. Because bipedals need several times less energy on the same distance than 4-legged creatures. At least, that's what I read about why humans are bipedals.

Me too.

To be fair, the stone artefacts attributed by "true" scientists to humans are much less impressive: http://www.nature.com/nature/journal/v521/n7552/full/nature14464.html[^]

There exists an optimum ratio between the linewidth and the interline spacing. I do not know its exact value but it is defined by the ease of following with the eyes the line and then switching to the next one. This is why the newspapers are printed in narrow columns instead of across the page.